Array classification:
1. Index Array. The index value starts at 0 and increments sequentially.
2. Declaring an array using the array () function
<?php //1. Assign a value directly to an array element to declare it $contact _index[0] = 1; $contact _index[1] = "Gao MoU"; $contact _index[2] = "a company"; $contact _index[3] = "Beijing"; $contact _index[] = "[email protected]"; Var_dump ($contact _index); $contact _key["ID"] = "2"; $contact _key["name"] = "peak"; $contact _key["Company"] = "Company B"; $contact _key["email"] = "[email protected]"; Var_dump ($contact _key); 2. Declare an array using the array () function $contact _key_array = Array ( "ID" = 1; " Name "= =" Peak One "; " Company "=" b Company "; " Email "=" [email protected]; ); Var_dump ($contact _key_array);? >
Traversal of the array:
1.for Statement Traversal array
2.foreach Statement Traversal array
<?php //Use the For statement to iterate through the array $cars =array ("Volvo", "BMW", "SAAB"); $arrlength =count ($cars); for ($i =0; $i < $arrlength; $i + +) { echo $cars [$i]; echo "<br>"; } ? ><?php
The foreach statement iterates through the associative array $age =array ("Bill" = "+", "steve" = "Notoginseng", "Peter" and "a"); foreach ($age as $x = + $x _value) { echo "key=". $x. ", value=. $x _value; echo "<br>"; }? >
Pre-defined arrays
1. It is a special array, no difference in operation mode.
2. Do not declare them, and each PHP script has a default.
3. They take effect automatically in the global scope.
Pre-defined array description
The $_server variable is set by the Web server or is directly associated with the execution environment of the current script
$_env the execution environment commits the variables to the script
$_get a variable submitted to the script via a URL request
$_post the variables submitted to the specimen via the HTTP POST method
$_request variables submitted to the script via the Get,post,cookie mechanism
$_files variables submitted to the script via HTTP POST file upload
$_cookie variables submitted to the script via the HTTP COOKIE method
$_session variables currently registered to the script session
$_globals contains a valid variable that refers to the global scope of each current script, and the key name of the array is the name of the global variable.
Merging arrays
The Array_merge () function merges the arrays together to return an array of unions.
Array Array_merge (array array1 array2.....arrayn)
<?php $fruits =array ("Apaple", "banana", "pear"); $numbered =array ("1", "2", "3"); $cards =array_merge ($fruits, $numbered);
Array ([0] = apaple [1] = banana [2] = pear [3] = 1 [4] = 2 [5] = 3)
?>
Splitting a fraction group
The Array_slice () function returns a portion of the array, starting with the key offset and ending at the offset+length position
Array array_slice (array array,int offset,[int length])
Offset is positive when starting from the front and negative when starting from the back
<?php $fruits = Array ("Apple", "Banana", "Orange", "Pear", "Grape", "Lemon", "watermelon"); $subset =array_slice ($fruits, 3); Print_r ($subset);
Output
Array ([0] = Pear [1] = Grape [2] = Lemon [3] = watermelon)?>
<?php
$fruits = Array ("Apple", "Banana", "Orange", "Pear", "Grape", "Lemon", "watermelon");
$subset =array_slice ($fruits, 2,-2);
Print_r ($subset);
Output
Array ([0] = Orange [1] = Pear [2] = Grape)
?>
Array header add element:
The Array_unshift function adds elements to the array header
<? PHP $fruits = Array ("Apple", "Banana", "Orange", "Pear", "Grape", "Lemon"); Array_unshift ($fruits, "AAAA", "BBBB"); Print_r ($fruits);//output//array ([0] = AAAA [1] = BBBB [2] = Apple [3] = = Banana [4] = Orange [5] =&G T Pear [6] = Grape [7] = Lemon)?>
Array header Delete element:
Array_shift Deleting an array header element
<?php $fruits = Array ("Apple", "Banana", "Orange", "Pear", "Grape", "Lemon"); Array_shift ($fruits); Print_r ($fruits);//output//array ([0] = Banana [1] = Orange [2] = = Pear [3] = = Grape [4] = Lemon)? ;
Add elements at the end of the array:
The Array_push function adds elements at the end of the array
<?php $fruits = Array ("Apple", "Banana", "Orange", "Pear", "Grape", "Lemon"); Array_push ($fruits, "AAAA", "BBBB"); Print_r ($fruits);//output//array ([0] = Apple [1] = Banana [2] = Orange [3] = Pear [4] = = Grape [5] =& Gt Lemon [6] = AAAA [7] = BBBB)?>
The trailing element of the array is deleted:
The Array_pop function deletes the trailing element of an array, returning the last element of the array.
<?php $fruits = Array ("Apple", "Banana", "Orange", "Pear", "Grape", "Lemon"); $result =array_pop ($fruits); Print_r ($result); echo "<br>"; Print_r ($fruits);//output//$result returns lemon//$fruits returns an array ([0] = Apple [1] = Banana [2] = Orange [ 3] = Pear [4] = Grape)?>
An array of PHP